A refrigerator is an electric home appliance that is used to store food in a refrigerated state or in a frozen state.
In recent years, the capacity of the refrigerator has been greatly increased, and a home bar, an ice maker, a shelf, or a door box has been mounted on the rear of a door of the refrigerator. In this type of refrigerator, when the door of the refrigerator is closed, the component mounted on the rear of the door of the refrigerator may interfere with a shelf or a drawer mounted in a storage compartment of a main body of the refrigerator.
In order to prevent such interference, the front end of a food storage unit (e.g. a shelf or a drawer) mounted in the storage compartment of the main body of the refrigerator, i.e. a refrigerating compartment or freezing compartment, is located at a place spaced apart from the front of the main body of the refrigerator by a predetermined distance.
For this reason, a user must put his/her hand into the storage compartment deeply in order to take out food stored in the food storage unit. Furthermore, it is difficult for the user to check the food stored in the rear portion of the storage compartment. These problems become more critical as the size of the refrigerator is increased.
Various methods have been proposed to solve the above problems. In particular, Korean Patent Application Publication No. 2010-0130357 (hereinafter, referred to as '357 patent), which was filed in the name of the applicant of the present application, discloses a refrigerator configured to have a structure in which a shelf or a drawer mounted in a refrigerating compartment or a freezing compartment is disposed at a receiving frame, the front end of an articulated link is connected to the bottom surface of a refrigerator door, and the rear end of the articulated link is connected to the receiving frame. When the refrigerator door is turned and opened, therefore, the receiving frame is moved forward, with the result that the shelf or the drawer is moved forward.
In the refrigerator having the above structure, the entire load of the shelf or the drawer is transferred to the receiving frame. In other words, the load of the shelf or the drawer and the load of the food stored on the shelf or in the drawer are concentrated on the receiving frame. For this reason, it important to design the receiving frame such that the receiving frame can sufficiently withstand the loads. As a result, the structure of the receiving frame is complicated, and the volume of the receiving frame is increased. Consequently, the weight of the receiving frame is increased. Furthermore, the capacity of the storage compartment is reduced due to the receiving frame.
In addition, in '357 patent, the link, which is interlocked with the door to move the receiving frame, is connected to the bottom surface of the receiving frame. Consequently, the force applied through the link acts on the bottom surface of the receiving frame. However, the center of gravity of the drawer is concentrated on the upper side of the bottom surface of the receiving frame. For this reason, the line of action of the force applied through the link and the line of action of the force applied due to the inertia of the drawer are not aligned with each other. Consequently, bending moment or shearing force acts on the receiving frame, with the result that the receiving frame may become deformed. This phenomenon becomes more serious as the weight of the food stored in the drawer is increased. In particular, in '357 patent, the load of the drawer accelerates deformation of the receiving frame together with the inertia of the drawer, since the load of the drawer is supported by the receiving frame.
In addition, in '357 patent, a rail mounted to the bottom surface of the frame must be maintained so as to be normally operated, since the load applied to the receiving frame is concentrated on the rail. In '357 patent, however, there are strong limitations in designing the rail in order to ensure that the rail has sufficient durability within predetermined standards.
In addition, in the structure which the entire load applied to the receiving frame is concentrated on the rail, the receiving frame nay easily shake during movement. If the rail or the receiving frame is deformed due to repetitive shaking of the receiving frame, the receiving frame is not moved stably.
Japanese Patent Application Publication No. JP2004-93039A (hereinafter, referred to as '039 patent) discloses a refrigerator configured to have a structure in which a shelf provided in a storage compartment is connected to a door via an arm such that the shelf is withdrawn by the arm when the door is opened. The arm is directly connected to the shelf. In order to simultaneously withdraw a plurality of shelves interlocked with the door, a plurality of arms is provided such that the arms are connected to the respective shelves.
In addition, the arms must be installed so as to correspond to the heights of the shelves, with the result that the positions at which the arms are installed are limited. In particular, a considerable portion of an arm connected to a shelf located at the middle of the storage compartment may be visible to a user.
In addition, in '357 patent and '039 patent, the structure of the receiving frame is exposed in the storage compartment. For this reason, the storage compartment does not have an aesthetically pleasing appearance. In addition, the storage space in the storage compartment reduced due to the receiving frame, and the circulation of cool air in the storage compartment is disturbed by the receiving frame.